An image sensor may be fabricated to have a large number of identical sensor elements (pixels), generally more than 1 million, in a (Cartesian) square grid. The pixels may be photodiodes, or other photosensitive elements, that are adapted to convert electromagnetic radiation into electrical signals. Recent advances in semiconductor technologies have enabled the fabrication of nanoscale semiconductor components such as nanowires.
Nanowires have been introduced into solid state image devices to confine and transmit electromagnetic radiation impinging thereupon to the photosensitive elements. These nanowires can be fabricated from bulk silicon which appears gray in color, although researchers have patterned the surface of silicon so it “looks” black and does not reflect any visible light.
However, nanowires configured to selectively absorb (or to lower the reflectance of) light at a predetermined wavelength have not been fabricated.